Cold-resistant master batch material and high-cold-resistant EVA composite foaming sole material

Abstract

The invention discloses a cold-resistant master batch material and a high-cold-resistance EVA composite foaming sole material, and relates to the technical field of foaming shoe materials, in particular to the cold-resistant master batch material which comprises main materials and auxiliary agents, the main materials comprise SEBS and rare earth cis-polybutadiene according to the mass ratio of 3: 1, and the auxiliary agents are added into the main materials; the cold-resistant master batch disclosed by the invention can be applied to shoe materials for improving ultralow-temperature toughness to achieve a cold-resistant effect. The shoe sole material comprises EVA, cold-resistant master batch, POE, a foaming agent, a cross-linking agent and an auxiliary agent, the cold-resistant master batch comprises SEBS and rare earth cis-polybutadiene, and the shoe material which is ultra-light in weight, low in low-temperature hardness change rate and high in rebound rate can be prepared from the material components.

Description

Technical Field

[0001] The present invention relates to the technical field of shoe materials, in particular to the technical field of foamed shoe materials. Background Art

[0002] In recent years, due to the continuous rise of the ice and snow economy, more and more people in the south travel to the north in winter. In order to adapt to the extremely harsh low temperature environment, new requirements are put forward for the cold resistance of shoes.

[0003] Currently, most outdoor products can only withstand moderate cold temperatures. Extreme cold conditions place even higher demands on the sole's cold resistance. However, after freezing ordinary EVA soles for two hours at temperatures below -15°C, their hardness increases by 18-25°C. This increased hardness significantly reduces various physical properties, such as flexibility, affecting wearing comfort and even causing the sole to break.

[0004] Existing solutions for cold-resistant sole materials mainly rely on the simple addition of SEBS or butadiene rubber. However, the sole materials obtained in this way have the following problems: the low-temperature rebound rate of the obtained sole material is less than 35%, and the density of the foamed material is greater than 0.15g / cm³, making it difficult to meet the lightweight and rebound performance requirements of the manufactured shoes. Summary of the Invention

[0005] The object of the present invention is to provide a cold-resistant masterbatch that can be applied to shoe materials to improve ultra-low temperature toughness and achieve cold resistance.

[0006] Another object of the present invention is to provide a highly cold-resistant EVA composite foam sole material and a preparation method thereof that is ultra-lightweight, has a low low-temperature hardness change rate and a high rebound rate.

[0007] To achieve the above object, the technical solution of the present invention is: a cold-resistant masterbatch, the material components of which include a main ingredient and an auxiliary agent, and the main ingredient includes SEBS and rare earth butadiene.

[0008] The SEBS and rare earth butadiene are mixed in a mass ratio of 3:1.

[0009] The SEBS model used is SEBS6553.

[0010] The rare earth butadiene is of model CB22.

[0011] A highly cold-resistant EVA composite foamed sole material comprises, by mass, 50-80 parts of EVA, 15-30 parts of cold-resistant masterbatch, 8-12 parts of POE, 2-4 parts of a foaming agent, 0.3-0.5 parts of a cross-linking agent, and 1-2 parts of an auxiliary agent. The cold-resistant masterbatch is made of a main ingredient and auxiliary agents, and the main ingredient comprises SEBS and rare earth butadiene sulfide.

[0012] The EVA has a VA content of 28-33%.

[0013] The ratio of SEBS to rare earth butadiene is 3:1.

[0014] The auxiliary agents include zinc oxide and stearate.

[0015] The SEBS model used is SEBS6553.

[0016] The rare earth butadiene is of model CB22.

[0017] The EVA model used is 33121.

[0018] The EVA used is model 7470.

[0019] The POE model is 8003.

[0020] The preparation method of the above-mentioned highly cold-resistant EVA composite foamed sole material comprises the following steps: first, mixing and granulating SEBS and rare earth butadiene succinate according to a mass ratio to obtain a cold-resistant masterbatch; then, weighing the raw materials of the highly cold-resistant EVA composite foamed sole material according to the component ratio; mixing the raw materials in an internal mixer in a staged mixing manner to obtain a mixed material; then, granulating the mixed material to obtain a granular material; and finally, taking a set amount of the granular material for mold foaming and shaping.

[0021] The temperature of the mold foaming is 180° C. and the time is 300 s.

[0022] The temperature of the setting treatment is 160° C. and the time is 750 s.

[0023] By adopting the above-mentioned technical solution, the present invention achieves the following beneficial effects: the cold-resistant masterbatch comprises a unique combination of two materials, each containing ultra-low-temperature rubber: SEBS with a glass transition temperature (Tg) of -85°C (which remains flexible even above -85°C) and rare earth cis-butadiene with a glass transition temperature (Tg) of -105°C, forming a "dual low-temperature phase" structure (particularly employing a 3:1 mass ratio). This structure represents a breakthrough in polymer material design, resolving the contradiction between single rubbers' inability to achieve both room-temperature performance and ultra-low-temperature toughness. The SEBS, as a continuous phase matrix, forms a continuous phase network, creating a flexible network throughout the material and providing foundational elasticity and strength. The rare earth cis-butadiene, as a dispersed phase, dispersed as tiny particles within the SEBS network, can act as "elastic islands" to absorb impact energy at ultra-low temperatures while maintaining high elasticity, inhibiting crack initiation and preventing crack propagation. Consequently, the cold-resistant masterbatch of the present invention exhibits impact resistance and brittle crack resistance in extremely cold environments.

[0024] The above-mentioned highly cold-resistant EVA composite foam sole material and preparation method thereof, whose main materials adopt the cold-resistant masterbatch with the above-mentioned effect and EVA, POE, etc., the combination of these raw materials has not been disclosed or used in the prior art. The material composition and the shoe material prepared therefrom have the excellent toughness provided by the cold-resistant masterbatch in extremely cold environments to play a cold-resistant effect, and can also achieve the ideal requirements of lightweight and elastic performance. The above-mentioned method can make the raw materials better exert their physical properties during the preparation process, thereby improving and achieving the effect of the material during the preparation. DETAILED DESCRIPTION

[0025] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0026] This embodiment discloses a highly cold-resistant EVA composite foam sole material, the material components of which mainly include EVA, cold-resistant masterbatch, POE, a foaming agent, a cross-linking agent and an auxiliary agent, wherein the cold-resistant masterbatch is made of a material including SEBS and rare earth butadiene.

[0027] EVA (ethylene-vinyl acetate copolymer) is a general-purpose polymer, formed by the copolymerization of ethylene and vinyl acetate. It exhibits excellent flexibility and elasticity, making it suitable for products requiring softness and elasticity. It also exhibits excellent cold resistance, maintaining excellent physical properties even at low temperatures. It exhibits excellent processability, making it easy to process and mold, suitable for various molding processes. Furthermore, some EVA materials are recyclable, meeting environmental protection requirements. Due to its excellent performance and wide range of applications, EVA holds significant value in various industries. In this embodiment, EVA with a VA content of 28-33% is preferred. In this embodiment, EVA grades 33121 (e.g., Formosa Plastics 28 Pa EVA) and 7470 (e.g., Polyurethane 33 Pa EAV) were used in pilot production trials, demonstrating excellent product performance. The two grades can be mixed or used separately.

[0028] The cold-resistant masterbatch is made from a main ingredient and auxiliary ingredients, the main ingredient being SEBS and rare earth cis-1,2-butadiene rubber (REE). SEBS (hydrogenated styrene butadiene block copolymer) is a linear triblock copolymer with polystyrene as the terminal segments and an ethylene-butene copolymer derived from hydrogenated polybutadiene as the middle elastic block. Due to its unique structure, the addition of high-viscosity naphthenic oil and silicone oil can increase the damping coefficient of the entire system during production, resulting in excellent shock absorption performance. Furthermore, because REE lacks unsaturated double bonds, the product's shock absorption performance is highly stable, maintaining stable performance over time. Rare earth cis-1,2-butadiene rubber (REE), also known as neodymium-based REE, is a type of cis-1,2-butadiene rubber produced through polymerization using a catalytic system based on the rare earth metal neodymium. It has a regular molecular chain structure and a cis content exceeding 98%, exhibiting high tensile strength, low rolling resistance, and wet skid resistance. In this embodiment, the SEBS used may be model SEBS6553, and the rare earth butadiene may be model CB22. Pilot production tests have shown excellent product performance. Furthermore, based on the material properties of SEBS and rare earth butadiene, and the material testing results from pilot production tests, the present invention preferably mixes SEBS and rare earth butadiene in a 3:1 mass ratio. Additional materials may include ST (approximately 0.3 parts by mass), a compatibilizer (approximately 0.1 parts by mass), and BIBP (approximately 0.2 parts by mass). In summary, a cold-resistant masterbatch is obtained, thanks to its unique combination of two materials with ultra-low-temperature properties: SEBS with a glass transition temperature (Tg) of -85°C (remaining flexible even above -85°C) and rare earth butadiene with a Tg of -105°C, creating a "dual low-temperature phase" structure (particularly using the aforementioned 3:1 mass ratio). This structure is a breakthrough in polymer material design, resolving the contradiction between single rubber's inability to balance room-temperature performance and ultra-low-temperature toughness. The SEBS material, as a continuous phase matrix, can form a continuous phase network, forming a flexible network that runs through the entire material, providing basic elasticity and strength. The rare earth butadiene serves as a dispersed phase, dispersed as tiny particles in the SEBS network, capable of absorbing impact energy as "elastic islands" at ultra-low temperatures, while still maintaining high elasticity, suppressing crack generation, and preventing crack propagation. Therefore, the cold-resistant masterbatch of the present invention can have impact resistance and anti-brittle cracking effects in extremely cold environments.

[0029] The POE (POE elastic composite material) is a multi-layer functional material made of polyolefin elastomer (POE). The material is based on a copolymer of ethylene and octene, and is polymerized by a solution method to form a structure in which crystalline regions and amorphous regions coexist. It has both the thermoplasticity of plastic and the elastomer of rubber. POE model 8003 can be used, such as the market material name DuPont POE.

[0030] The foaming agent, cross-linking agent and auxiliary agent may be conventionally used materials, such as ST (stearic acid), ZNO (zinc oxide), ZNST (zinc stearate), BIBP (odorless adhesive), AC6000 (high temperature foaming agent), etc.

[0031] Pilot production tests have shown that the materials of the present invention preferably comprise 50-80 parts EVA, 15-30 parts cold-resistant masterbatch, 8-12 parts POE, 2-4 parts foaming agent, 0.3-0.5 parts cross-linking agent, and 1-2 parts auxiliary agent, by weight. The resulting product demonstrates the aforementioned objectives and effects of the present invention. The following demonstrates the characteristics of the sole material and preparation method of the present invention through performance testing of several component ratios and products obtained from pilot production tests.

[0032] Formula Ratio 1

[0033] Raw material name Parts by weight 33121 (Sub 33 Pa EVA) 35 7470 (Formosa 28 Pa EVA) 10 Cold resistance master batch 20 8003 (Dupont POE) 10 ST (Stearic acid) 0.3 ZNO (Zinc oxide) 0.8 ZNST (Zinc stearate) 0.5 BIBP (Odorless adhesive) 0.35 AC6000 (High temperature foaming agent) 3.2

[0034] Recipe 2

[0035] Raw material name Parts by weight 33121 (Sub 33 Pa EVA) 40 Cold resistance master batch 25 8003 (Dupont POE) 10 ST (Stearic acid) 0.3 ZNO (Zinc oxide) 0.8 ZNST (Zinc stearate) 0.5 BIBP (Odorless adhesive) 0.35 AC6000 (High temperature foaming agent) 3.2

[0036] Recipe Ratio 3

[0037] Raw material name Parts by weight 33121 (Sub 33 Pa EVA) 35 7470 (Formosa 28 Pa EVA) 10 8003 (Dupont POE) 10 ST (Stearic acid) 0.3 ZNO (Zinc oxide) 0.8 ZNST (Zinc stearate) 0.5 BIBP (Odorless adhesive) 0.35 AC6000 (High temperature foaming agent) 3.2

[0038] Formula Ratio 4

[0039] Raw material name Parts by weight 33121 (Sub 33 Pa EVA) 25 7470 (Formosa 28 Pa EVA) 20 8003 (Dupont POE) 10 ST (Stearic acid) 0.3 ZNO (Zinc oxide) 0.8 ZNST (Zinc stearate) 0.5 BIBP (Odorless adhesive) 0.35 AC6000 (High temperature foaming agent) 3.2

[0040] The following is the performance test of the product types obtained by the above four formulation ratios.

[0041] Performance Formulation ratio 1 Formulation ratio 2 Formulation ratio 3 Formulation ratio 4 Hardness (Shore C 23℃) 41 38 49 44 Hardness (Shore C -15℃ 2h) 45 44 65 66 Density (g / cm3) 0.14 0.137 0.138 0.135 Layered tear (N / cm) 16 15 18 12 Compression distortion (%) 35 34 42 40 Resilience (%) 65 68 35 38 Tensile strength (MPa) 2.0 1.9 1.2 1.3

[0042] The above-mentioned formula ratios 1 and 2 are products with added cold-resistant masterbatch. Formula ratio 1 is a mixture of two EVA types, and formula ratio 2 is a single type. Formula ratios 3 and 4 are products without added cold-resistant masterbatch. They are all mixtures of two EVA types, and the rest of the materials are the same. In more performance tests, products with added cold-resistant masterbatch showed differences in hardness, rebound rate and other properties with a cold-resistant masterbatch ratio of 3:1. It can be seen that the cold-resistant masterbatch with this ratio has outstanding characteristics and significant improvements. In addition, the sole material obtained above has the excellent toughness provided by the cold-resistant masterbatch in extremely cold environments, which plays a role in cold resistance. In addition, the selection of main ingredients and the characteristics of each main ingredient enable the shoe material to achieve the ideal requirements of lightweight and elastic performance. Through the above four ratios and performance tests with only differences in EVA and cold-resistant masterbatch, it can be clearly seen that the sole material product made with the addition of cold-resistant masterbatch has a smaller change in hardness at low temperatures and maintains a higher rebound rate. Compared with other ratios without additions, there are obvious differences in hardness and rebound rate at low temperatures, and other performance differences are relatively small, which also reflects the special features of the high cold-resistant EVA composite foam sole material of the present invention compared with existing materials.

[0043] In addition, the preparation method of the highly cold-resistant EVA composite foam sole material of the present invention has been improved in the existing conventional production and preparation of sole materials, which can enable the raw materials to better exert their physical properties during the preparation process, thereby improving and achieving the effect of the material during the preparation.

[0044] The preparation method of a high cold-resistant EVA composite foaming sole material of the present invention comprises the following: first, SEBS and rare earth butadiene succinate are mixed and granulated according to the mass ratio to obtain a cold-resistant masterbatch, then the high cold-resistant EVA composite foaming sole material is weighed according to the component ratio, mixed in a staged mixing manner in an internal mixer to obtain a mixed material, then the mixed material is granulated to obtain a granular material, and finally, the granular material is measured according to the set amount for mold foaming and shaping treatment. During the preparation process, the temperature of the mold foaming is preferably 180°C, the time temperature is preferably 300s, and the temperature temperature of the shaping treatment is preferably 160°C, and the time temperature is preferably 750s. The staged mixing method of the above-mentioned preparation method can be used to mix different raw material physical properties to achieve better physical properties, and the temperature and time parameters of the mold foaming and shaping treatment have a role in improving product performance.

[0045] The above embodiments do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A cold-resistant masterbatch, characterized in that: The material composition comprises a main material and an auxiliary agent, wherein the main material comprises SEBS and rare earth butadiene.

2. A cold-resistant masterbatch according to claim 1, characterized in that: The SEBS and rare earth butadiene are mixed in a mass ratio of 3:

1.

3. A cold-resistant masterbatch according to claim 1 or 2, characterized in that: The SEBS adopts the model SEBS6553, and / or the rare earth butadiene adopts the model CB22.

4. A highly cold-resistant EVA composite foam sole material, characterized in that: The material components include EVA, cold-resistant masterbatch, POE, foaming agent, cross-linking agent and auxiliary agent, and the cold-resistant masterbatch includes SEBS and rare earth butadiene.

5. The high cold-resistant EVA composite foam sole material according to claim 4, characterized in that: The EVA has a VA content of 28-33%, and / or the ratio of SEBS to rare earth butadiene is 3:1, and / or the auxiliary agents include zinc oxide and stearate.

6. A highly cold-resistant EVA composite foam sole material according to claim 4 or 5, characterized in that: The components of the material are calculated by mass: 50-80 parts of EVA, 15-30 parts of cold-resistant masterbatch, 8-12 parts of POE, 2-4 parts of foaming agent, 0.3-0.5 parts of cross-linking agent, and 1-2 parts of auxiliary agent.

7. The high cold-resistant EVA composite foam sole material according to claim 6, characterized in that: Including 35 parts of EVA model 33121, 10 parts of EVA model 7470, 20 parts of cold-resistant masterbatch, 10 parts of POE model 8003, 0.3 parts of stearic acid, 0.8 parts of zinc oxide, 0.5 parts of zinc stearate, 0.35 parts of odorless adhesive, and 3.2 parts of high-temperature foaming agent; Alternatively, it includes 40 parts of EVA with model number 33121, 225 parts of cold-resistant masterbatch, 10 parts of POE with model number 8003, 0.3 parts of stearic acid, 0.8 parts of zinc oxide, 0.5 parts of zinc stearate, 0.35 parts of odorless adhesive, and 3.2 parts of high-temperature foaming agent.

8. The high cold-resistant EVA composite foam sole material according to claim 4 or 5, characterized in that: The SEBS adopts the model number SEBS6553, the rare earth butadiene adopts the model number CB22, the EVA adopts the model number 33121, the POE adopts the model number 8003 and / or the EVA adopts the model number 7470.

9. A method for preparing a highly cold-resistant EVA composite foam sole material according to any one of claims 4 to 8, characterized in that: The preparation method comprises the following steps: first, mixing SEBS and rare earth butadiene succinate according to a mass ratio to obtain a cold-resistant masterbatch; then, weighing raw materials of the highly cold-resistant EVA composite foamed sole material according to a component ratio; mixing the raw materials in a staged mixing manner in an internal mixer to obtain a mixed material; then, granulating the mixed material to obtain a granular material; and finally, taking a set amount of the granular material to perform mold foaming and shaping treatment.

10. The method for preparing a highly cold-resistant EVA composite foamed shoe sole material according to claim 9, wherein: The temperature of the mold foaming is 180° C. and the time is 300 seconds, and / or the temperature of the shaping treatment is 160° C. and the time is 750 seconds.